1. Field of the Invention
The present invention relates to data broadcasting (datacasting), and in particular, to peer-to-peer datacasting in a broadcasting network, for example, a television (TV) broadcasting network.
2. Description of the Related Technology
In addition to audio and video (A/V) services, advanced digital TV services offer a data service in which software objects are distributed via a digital broadcasting channel. The software objects include, but are not limited to, electronic program guide (EPG), software component (e.g., Java applets, library, and web components), software application (e.g., game), and firmware image, etc. For this purpose, advanced television systems committee (ATSC) and digital video broadcasting (DVB) specify data broadcasting services (also known as datacasting). Digital broadcasting provides a one-way channel from a broadcaster to a number of client devices, but lacks a return channel from the client devices to the broadcaster. Without the return channel, the broadcasters do not know how many client devices need the software object and whether the client devices receive it when the software object is broadcasted. To compensate the lack of the return channel, the datacasting service of this type uses a carousel server which repeatedly broadcasts the software objects in a continuous cycle over a digital broadcasting channel. The client devices may choose to ignore the software object or to wait for another software object until it is broadcasted by the carousel server.